1977 530i as a Chump Car

[Zaider]

Hey Everyone,

New member here and looking for some information. My friends and I have just purchased a '77 530i which we are planning on using as a Chump Car entry.

For those of you unfamiliar with Chump Car, the premise is that you bring and race a $500 car. The event here in Calgary is two 7 hour enduro races (Saturday and Sunday). We've chosen the E12 as our platform.

With the $500 limit, including modifications (safety mods are exempt) we're quite limited in what we can do to improve the performance. Our E12 is probably quite close to the $500 assessed limit.

So, first question is... what areas are lacking in the E12? I've been reading a fair bit so far and from what I can tell, the brakes are quite strong on the E12. How's the suspension? Are swaybars a common modification?

We also have the ability to run open-header or even open-port. We'll probably do at least open-header. Is the scavenging of the headers that big a deal that we should avoid going with open-port?

How's the shifter linkage? We're planning on switching out as many bushings as we can (especially engine, trans and rear diff).

We'll be completely stripping the car of as much weight as possible. Seats, carpets, liners, plastic, dash, etc will all go. We'll be keeping the heater as anyone who's ever been to Calgary in May will know, its probably going to be quite cold.

Anyway, Im really looking forward to getting to know more about BMW's. I would say that my friends and I are fairly mechanically capable. We've just finished a succcessful JDM swap of an STI engine/trans and much more into my 2002 Subaru 2.5RS and its running really well.

I really appreciate any and all advice. Thanks a lot!

- Z

[Zaider]

Some pictures of the car! Its up in Edmonton right now and hasn't been registered for the last year. We'll be bringing it down next weekend.


image-2 by zcherniawsky, on Flickr


image-3 by zcherniawsky, on Flickr


image-7 by zcherniawsky, on Flickr


image-6 by zcherniawsky, on Flickr


image-10 by zcherniawsky, on Flickr


image-8 by zcherniawsky, on Flickr

[Jeff Dennis]

Looks like a good base for your project...it should be a 75 or 76 with the early style hood and the interior looks very clean. Check for stress cracking at the body to rear diff mount and have fun!

[Velocewest]

Does it run? If yes, good; if no, the early L-jet can be "interesting" to troubleshoot, but you've come to the right place for help.

BMW uses a pretty efficient combustion chamber design (kind of a "triple hemi", they call it 'drikugelwernenwennbraum' or something close). This car probably has a thermal reactor (old-skool catalyst) bolted to the exhaust side of the head. Toss it, and get plain cast iron manifolds. Then run a short exhaust pipe out the side. Keep in mind, you can't open up the intake side, so opening up the exhaust beyond removing the cat and muffler will net very little. And getting more than about 160 hp out of that engine will cost you WAY more than your allowed budget. Focus on reliability. The endurance racer's creed is "To finish first, first you have to finish..."

Suspension is good, the car should have at least a front anti-roll bar if not front and rear. Larger bars are available from other factory fitments. Bracing the front and rear strut towers will add stiffness. If you'll be running on pavement or smooth dirt, you can nick a coil out of the springs to bring the car down and gain some useful camber front and rear. Put money into tie rod ends if needed. The bushing are pretty robust and a PITA to change.

Cooling can be an issue on early cars like this one, but if you're running in cold weather it's unlikely to be a problem. Just be sure you bleed the cooling system well to get all the air pockets out, both for reliability and heater performance!

You might want plate the trunk floor around the diff mount for extra strength. These cars suffer extensive tinworm where the roads are salted, and you don't want the diff going AWOL 3 or 4 hours in.

[JoshInAtlanta]

Cool Chump Car,,,,

[GripGreg]

The bleeder screw is on top of water pump. I suggest you put the rear wheels in the lowest part of the driveway so the front is about a foot higher, drain the radiator from the drain plug at the bottom of the radiator & re-fill with fresh Prestone stuff & top off with water. This should be a decent percentage between the two. Crack open the bleeder screw is the last thing to do. Add water til it runs outta the bleeder w/o air bubbles.
If you need to make it lighter & it's a manual sunroof, send it to me, I need one for my '75!
You guys in the P-NorWest seem to have all the '75's!
Have fun,,,,Greg

[Zaider]

Looks like a good base for your project...it should be a 75 or 76 with the early style hood and the interior looks very clean. Check for stress cracking at the body to rear diff mount and have fun!

Hmm. The registration says it is a 1977, could it just be an early variant?

Does it run? If yes, good; if no, the early L-jet can be "interesting" to troubleshoot, but you've come to the right place for help.

BMW uses a pretty efficient combustion chamber design (kind of a "triple hemi", they call it 'drikugelwernenwennbraum' or something close). This car probably has a thermal reactor (old-skool catalyst) bolted to the exhaust side of the head. Toss it, and get plain cast iron manifolds. Then run a short exhaust pipe out the side. Keep in mind, you can't open up the intake side, so opening up the exhaust beyond removing the cat and muffler will net very little. And getting more than about 160 hp out of that engine will cost you WAY more than your allowed budget. Focus on reliability. The endurance racer's creed is "To finish first, first you have to finish..."

Suspension is good, the car should have at least a front anti-roll bar if not front and rear. Larger bars are available from other factory fitments. Bracing the front and rear strut towers will add stiffness. If you'll be running on pavement or smooth dirt, you can nick a coil out of the springs to bring the car down and gain some useful camber front and rear. Put money into tie rod ends if needed. The bushing are pretty robust and a PITA to change.

Cooling can be an issue on early cars like this one, but if you're running in cold weather it's unlikely to be a problem. Just be sure you bleed the cooling system well to get all the air pockets out, both for reliability and heater performance!

You might want plate the trunk floor around the diff mount for extra strength. These cars suffer extensive tinworm where the roads are salted, and you don't want the diff going AWOL 3 or 4 hours in.

Thanks for all the advice (goes for everyone else too!)

Yeah, we're not too worried about power for the moment but why can we not open up the intake. I haven't gotten a close look at it, but from the looks of it, the stock intake seems pretty restrictive. We're not running at night, so we were thinking about removing one of the headlights and running almost a ram-air intake through one of them. This has all just been discussed over beers without actually seeing the car in person so... we might be completely out to lunch.

Then engine runs. My buddy took it out in the neighbourhood and said everything feels really good.

We'll look into cutting the springs and reinforcing the rear diff.

[cowtownbimmer]

Thanks for all the info guys,

The car runs pretty decent, sounds like the muffler has a leak in it, but I didn't really care about that.

the guy said the engine was rebuilt a couple years back, and I believe him. it idled smoothly, and drove pretty good. (well for the 4 block I drove it, since it wasn't registered he didn't want me taking it on the highway)

I think the Thermal reactor is the first thing to go (well after all the fluids)
theres a '79 633i at the picknpull here in calgary. would those headers work? and anything else I should pull from that car?

a lot of good suggestions so far. thanks guys.

[Mike W.]

You called it right on getting rid of the themo reactors, they hurt power and kill heads thru massive heat. But a 79 E24 would have the same thermos. E12's got regular manifolds in 79, but E23's and E24's didn't until '80. E28 manifolds will fit right, but the downpipes won't. But yeah, loose the thermos for racing.

[John in Simi Valley]

Zaider, I like the green color.
What is all that white stuff on the ground?

As you know, endurance events are way more about mental, physical and mechanical stamina than massive HPs. As Pierre says, it's not the car but the NUT behind the wheel. It's an admirable undertaking - very best wishes, and be sure to take lots of photos and STAY WARM!

[Zaider]

Zaider, I like the green color.
What is all that white stuff on the ground?

LOL. The car will be getting painted. We're currently thinking the classic white with the three BMW stripes, but... we'll see.

The white stuff? Oh, that's just the colour of the ground up here in Canada. Well, for 8 months out of the year... aside from a couple weeks of -30*C, its actually been kinda nice this winter so far.

[cowtownbimmer]

You called it right on getting rid of the themo reactors, they hurt power and kill heads thru massive heat. But a 79 E24 would have the same thermos. E12's got regular manifolds in 79, but E23's and E24's didn't until '80. E28 manifolds will fit right, but the downpipes won't. But yeah, loose the thermos for racing.

Thanks for the info. that's really good to know.

would a 86 735i fit? I think that's still the e23, but since the displacement is quite different, I don't know if that would work, or maybe a better question to ask, so I don't keep asking the same thing about different donar cars, would any headers from any variants of the m30 egine work (post 1980 of course)?

Thanks

[GripGreg]

If you have a $500 limit can you afford to paint it? It won't go faster in white, I don't think.

[Mike W.]

You called it right on getting rid of the themo reactors, they hurt power and kill heads thru massive heat. But a 79 E24 would have the same thermos. E12's got regular manifolds in 79, but E23's and E24's didn't until '80. E28 manifolds will fit right, but the downpipes won't. But yeah, loose the thermos for racing.

Thanks for the info. that's really good to know.

would a 86 735i fit? I think that's still the e23, but since the displacement is quite different, I don't know if that would work, or maybe a better question to ask, so I don't keep asking the same thing about different donar cars, would any headers from any variants of the m30 egine work (post 1980 of course)?

Yes it would be an E23, the manifolds will bolt up fine, but the downpipes will likely hit. If they're cheap enough it might be worth it to get them and just take a torch to them to bend them if needed.

Thanks

[Jeff Dennis]

I have an extra set of early cast iron headers but you may be able to find them up there.
The part number and drawing should be on Real OEM for Bavaria sedans they use the M30 engine.